I didn't checked the link but if your question about the accuracy, no one can
accurate predict the price movement in my opinion. Some even says that TA is not applicable to crypto market so I doubt that they can see or predict it 100%.
If I were in your shoes, would rather study the market myself, do my own research and homework before investing on anything. I can't say they are scam, but I'm sure they are trying to make money here.
I do not believe in predictions, i follow fundamental and technical analysis only but even with being expert at FA and TA you cannot be right 100% of the time. So nothing can be 100% true in the markets.
Exactly, TA can be used as a guide, but its nowhere accurate. The market is very volatile and unstable and the balance can go either way, any direction in an instant.